Superpave Asphalt Binders Aging and what they mean to the specification John D Angelo D Angelo Consulting, LLC johndangelo@dangeloconsultingllc.com
Stiffness (Response to Load) elastic viscous elastic solid viscous fluid -30 25 60 135 Temperature, C
Superpave Asphalt Binder D Angelo Consulting Specifications Performance-Based to minimize permanent deformation (rutting) fatigue cracking (repeated load failure) low temperature cracking or single event cracking Physical Properties measured on aged binder
Grading System Based on Climate Performance Grade PG 58-28 Accumulated days of high pavement design temp Min pavement design temp
CEC Avg 7-day Max, o C 1-day Min, o C How the PG Spec Works Spec Requirement Remains Constant > 230 o C < 3 Pa. s @ 135 o C > 1.00 kpa > 2.20 kpa 20 Hours, 2.07 MPa < 5000 kpa PG 46 PG 52 PG 58 PG 64 PG 70 PG 76 PG 82-34 -40-46 -10-16 -22-28 -34-40 -46-16 -22-28 -34-40 -10-16 -22-28 -34-40 -10-16 -22-28 -34-40 -10-16 -22-28 -34-10 -16-22 -28-34 (Flash Point) FP (Rotational Viscosity) (Dynamic Shear Rheometer) RV 46 52 58 64 70 76 82 (ROLLING THIN FILM OVEN) RTFO Mass Loss < 1.00 % (PRESSURE AGING VESSEL) 90 90 100 100 100 (110) 100 (110) 110 (110) (Bending Beam Rheometer) BBR Physical Hardening (Direct Tension) ORIGINAL PAV S < 300 MPa m > 0.300 ( Bending Beam Rheometer) BBR S Stiffness & m - value Report Value F. Strain > 1.00 % 52 58 (Dynamic Shear Rheometer) DSR G*/sin δ 46 52 58 64 70 76 82 (Dynamic Shear Rheometer) DSR G*/sin δ DSR G* sin δ 10 7 4 25 22 19 16 13 10 7 25 22 19 16 13 31 28 25 22 19 16 34 31 28 25 22 19 37 34 31 28 25 40 37 34 31-24 -30-36 0-6 -12-18 -24-30 -36-6 -12-18 -24-30 0-6 -12-18 -24-30 0-6 -12-18 -24-30 0-6 -12-18 -24 0-6 -12-18 -24 DT Test Temperature Changes RWM 28-24 -30-36 0-6 -12-18 -24-30 -36-6 -12-18 -24-30 0-6 -12-18 -24-30 0-6 -12-18 -24-30 0-6 -12-18 -24 0-6 -12-18 -24
Production Rutting Fatigue Cracking Thermal Cracking D Angelo Consulting Time DTT RV DSR BBR RTFO - aging No aging PAV - aging
Aging - How? Early: To simulate the aging that occurs due to construction and initial service, we are going to employ the Rolling Thin-Film Oven (RTFO). This is a standard AASHTO test method, T 240. Spec.: 85 minutes, 163 C, 400 ml of air per minute, 15 rpm
Rolling Thin Film Oven 163 C controls fan air jet bottle carriage
Pressure Aging Vessel air pressure temperature probe asphalt pressure vessel sample rack sample pan
Construction D Angelo Consulting Time [RV] No aging Rutting [DSR] Fatigue Cracking RTFO - aging [DTT] [BBR] PAV - aging Low Temp Cracking
Grading of Asphalt binder D Angelo Consulting Original PROPERTY ORIGINAL BINDER Specific Gravity Flash Point, C ( F) COC Viscosity, Pa s Dynamic Shear (G*/sin, 10 rad./sec.), kpa AASHT O TEST METHO D SPECS RESULTS by sample label info below -1-2 -3-4 AASHTO M 320, Table 1 Requirements (DSR s & BBR s reported above and below passing 15.6 C T 228 Report 1.0146 1.015 1.022 1.018 T 48 230 min. 552 (289) 536 (280) 530 (276) 540 (282) 135 C T 316 3.0 max. 0.34 0.29 0.375 0.4 58 C -- 1.74 -- -- 64 C T 315 1.0 min. 1.07 0.826 1.35 1.52 70 C 0.529 -- 0.657 0.74
Grading of Asphalt binder D Angelo Consulting RTFOT PROPERTY RTFOT RESIDUE AASHTO M 320 Requirements Mass Change, % (Mass Loss is reported as Negative) Dynamic Shear (G*/sin, 10 rad./sec.), kpa AASHT O TEST METHO D SPECS RESULTS by sample label info below -1-2 -3-4 T 240 1.0 max. -0.065-0.17-0.173-0.109 58 C -- 6.1 -- -- 64 C 4.08 2.91 -- -- T 315 2.2 min. 70 C 1.98 1.41 2.62 2.99 76 C -- -- 1.28 1.46
Grading of Asphalt PAV Dynamic Shear (G* sin, 10 rad./sec.), kpa Creep Stiffness PROPERTY Stiffness, MPa (60 sec.) m Value Stiffness, MPa (60 sec.) m Value Stiffness, MPa (60 sec.) m Value 19 C 4,120 -- 4,230 4,480 16 C 5,790 4,810 5,940 6,210 13 C -- 6,760 -- -- -12 C -18 C -24 C AASHT O TEST METHO D T 313 SPECS 300 max. 92 -- 102 111 0.300 min. 0.322 -- 0.317 0.352 300 max. 191 157 208 197 0.300 min. 0.296 0.311 0.29 0.299 300 max. -- 312 -- -- 0.300 min. RESULTS by sample label info below -1-2 -3-4 -- 0.287 -- -- AASHTO M 320 SUPERPAVE Binder Grade, PG: AASHTO M320, Table 1, Continuous PG: 64-22 58-28 64-22 64-22 64.6-27.1 62.5-30.8 66.5-25.8 67.5-27.9
PG Continuous Grade min. AASHTO M 320 SUPERPAVE Binder Grade, PG: 64-22 58-28 64-22 64-22 AASHTO M320, Table 1, Continuous PG: 64.6-27.1 62.5-30.8 66.5-25.8 67.5-27.9
ASTM D 3384 Table 4 Absolute Viscosity, P 60 C D2171 1,000±200 Kinematic cst, min. PROPERTY ASTM D 3381-14, Table 4 Requirements: As Received Viscosity, Flash Point, COC, C ( F) Solubility in TCE, %, min. AC-10 AC-20-1 -2-3 -4 2,000± 400 1,921 1,452 2,392 2,417 135 C D2170 250 300 371 313 408 430 D92 219 (425) 232 (450) 289 280 276 282 D2042 99 99 99.95 99.92 99.94 99.94 Specific Gravity 15. C D70 Report Report 1.0146 1.015 1.022 1.018 Penetration (100 g, 5 sec.), dmm Softening Point, C ( F) TEST METHOD SPECS RESULTS; Sample # 25 C D5 Report Report 65 77 62 59 D36 Report Report 51.7 50 53.3 52.8 Penetration Index 2 Annex A -1.5 to +1.0-0.142-0.116 0.121-0.125
ASTM D 3384 Table 4 TEST SPECS RESULTS; Sample # PROPERTY Penetration Index METHOD e AC-10.5 to AC-20.0 0. -1 0. -2 6 0. -3 0. -4 5 RTFOT Residue: Mass Change, %, max. 1 Absolute Viscosity, P, Max. Ductility, cm, min (5 cm/min.) -0.066-0.062-0.06-0.112 60 C D2171 5,000 8,000 9,245 8,016 13,513 18,803 25 C D113 75 50 29 42.4 25.4 22 Would you want to use this asphalt on your pavement?
No Control of Aging on The RTFOT PROPERTY ORIGINAL BINDER Specific Gravity Flash Point, C ( F) COC Viscosity, Pa s Dynamic Shear (G*/sin, 10 rad./sec.), kpa AASHT O TEST METHO D SPECS RESULTS by sample label info below -1-2 -3-4 AASHTO M 320, Table 1 Requirements (DSR s & BBR s reported above and below passing 15.6 C T 228 Report 1.0146 1.015 1.022 1.018 T 48 230 min. 552 (289) 536 (280) 530 (276) 540 (282) 135 C T 316 3.0 max. 0.34 0.29 0.375 0.4 58 C -- 1.74 -- -- 64 C T 315 1.0 min. 1.07 0.826 1.35 1.52 70 C 0.529 -- 0.657 0.74 RTFOT as Negative) RESIDUE D -1-2 -3-4 AASHTO M 320 Requirements 58 C -- 6.1 -- -- Dynamic Shear (G*/sin, 10 64 C 4.08 2.91 -- -- T 315 2.2 min. rad./sec.), kpa 70 C 1.98 1.41 2.62 2.99 76 C -- -- 1.28 1.46
PAV aging may not be capturing the aging issues with binders. We may need control of aging on RTFOT. D Angelo ConsultingNeeded Modification to the PG Spec
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